An image forming system in which a client terminal that generates print data and a printer that prints the generated print data are connected directly or indirectly via a server or the like is known. In the image forming system of this type, one of apparatuses which form the system sequentially registers a print job in a print job queue and manages it based on a print job request issued by the client terminal (queuing control). For example, in an arrangement in which the client terminal and printer are one-to-one connected, the client terminal performs queuing control of a print job issued by itself.
Also, an image forming system in which a client terminal, printer, and printer server are connected via a network is well known. In such image forming system, the printer server manages the execution order by the printer of print jobs issued by the client terminal using a print job queue. In general, to such network, a plurality of client terminals and a plurality of printers can be connected. Therefore, the printer server performs queuing control of print jobs issued by the plurality of client terminals, distributes the print jobs to the plurality of printers to be shared, and executes these print jobs in an appropriate order.
Also, an advanced-function printer which can execute print job queuing control processing of the printer server has been proposed. With such advanced-function printer, since the printer itself performs queuing control of print jobs requested from a plurality of client terminals, no printer server is required.
In an image forming system in which a plurality of types of printers are connected to be able to be shared by a plurality of clients, the user who issues a print job output request must recognize the characteristics of these plurality of printers and must select a printer according to the contents to be printed. For this reason, the load on the user who wants to print becomes heavier. To solve such problem, in recent years, a technique for providing a function of automatically selecting an optimal printer in correspondence with the attribute of a print job to the printer server has been proposed.
Even in an image forming system which comprises the printer server having a function of automatically selecting an optimal printer, the user often directly selects a convenient printer for him or her (e.g., a printer closest to the user) so as to print out data. Therefore, even in any of the above image forming systems, the user need designate a desired printer and set detailed information corresponding to the characteristics of the designated printer upon generation of a print job. As a result, the load on the user becomes heavier, and unwanted printing occurs despite of the intention of the user due to setting errors and the like upon setting the detailed information in the printer.
As described above, the user who issued a print job must frequently partially modify information of the print job after the print job is issued and must re-issue the print job. However, in a general image forming system, after a print request is issued (print job is enqueued), the user must request the system administrator to cancel the print job or must cancel the print job by himself or herself, and must issue an output request of the modified print job again. Hence, the operations become complicated, and the traffic on the network increases.
To solve the aforementioned problems, Japanese Patent Laid-Open No. 11-95942 allows to change setting information of a print job even after the print job is enqueued.
However, in the method described in Japanese Patent Laid-Open No. 11-95942, the execution order of replacement print jobs is not mentioned. It is sometimes desirable to place a new print job which is input in a replacement printing mode back to an original position in preference to convenience of the user, but it is sometimes desirable to postpone such job to the backmost position in preference to convenience of other users.